The principle sugars from plant materials, glucose and fructose, have been shown to be useful renewable starting materials for the production of a variety of organic compounds that may substitute for petroleum based compounds. For example, the furan compound, 2,5-(hydroxymethyl)furaldehyde, also known as 2,5-(hydroxymethyl)furfural (HMF) a five membered heterocycle obtained by dehydration of a hexose, most efficiently from fructose.
HMF has strong potential in industrial and commercial applications especially for polymer applications due to its multi-functionality which allows for use as a monomer in polymerization reactions.

Generation of HMF by dehydration of fructose produces three equivalents of water as by products, and the formation of 3 double bonds (two alkenes and one aldehyde). In order to compete as substitutes or replacements in the chemicals market, HMF must be produced at relatively low cost. The production of HMF has been studied for years, but an efficient and cost-effective method of producing HMF has yet to be found. Extended reaction times, high temperatures and pressures cause complications to arise from the rehydration of HMF after the dehydration occurs, which often yields the byproducts of levulinic acid and formic acid. Another competing side reaction is the polymerization of HMF and/or fructose to form humin.
A low yield of HMF is typically obtained when the synthesis is performed in aqueous conditions because of the low selectivity of the dehydration reaction. Low selectivity simultaneously leads to increased polymerization reactions and humin formation, which also interfere with the synthesis of HMF. Where attempts have been made to solve problems associated with aqueous systems, the HMF reaction product is generally sequestered by organic solvent extraction or adsorption onto a resin as soon as it is formed. These systems fail to directly address the issue of low selectivity for HMF. In addition, these systems generally suffer from high dilution or partially irreversible adsorption of HMF and increase cost due to handling and use of the organic solvents or resins. Thus, a selective aqueous reaction system wherein HMF is the predominant product formed at would be desirable.
Levulinic acid is made by dehydration of hexose, which generates HMF as an intermediate, followed by deformylation resulting in the loss of formic acid. Levulinic acid and levulinate esters have been used as important intermediates in pharmaceutical and fine chemical processes.

Anhydrosugar alcohols, such as sorbitan and isosorbide derived from glucose, are mono cyclic and bi-cyclic ring compounds that are made by the dehydration of 1 or 4 water molecules, respectfully, from a hexitol, which is typically made by hydrogenation of a hexose.

Of all the known isohexides, isosorbide is considered to be one of high importance because of its use in the formation of pharmaceutical compounds, in food production, cosmetic production, plastic and polymer production, and in other potential industrial uses such as in the production of polyurethane, polycarbonate, polyesters, and polyamides (Stoss and Hemmer, 1991).
Several processes for the production of anhydrosugar alcohols (including isohexides such as isosorbide) have been reported. For example, PCT application number PCT/US99/00537 (WO 00/14081), discloses collecting methods and a continuous production method with recycling of organic solvent. Most methods involve the use of concentrated acids and organic solvents. Goodwin et al., Carbohydrate Res. 79:133-141 (1980) have disclosed a method involving the use of acidic-cation-exchange resin in place of concentrated, corrosive acids, but with low yield of isosorbide product. An alternative is the supersaturation-based method, as disclosed in U.S. Pat. No. 4,564,692 (Feldmann, et al., Jan. 14, 1986). However, a need continues for a process for production of very pure dianhydrosugaralcohols, at reasonable yields.
These dehydrated ring derivatives of hexoses, may further be used for making several other compounds, for example, by making ether derivatives of the free alcohol groups as illustrated below:
                Where R can be alkyl, allyl, or aryl        
For example, the anhydrosugar alcohol, isosorbide, can be used as a starting material in the formation of isosorbide dimethyl ether and isosorbide dinitrate or as an intermediate in various organic synthesis reactions. Isosorbide dimethyl ether is useful as an industrial solvent, a pharmaceutical additive, and in personal care products, while isosorbide dinitrate is useful as a medication to relieve the pain of angina attacks or reduce the number of such attacks by improving blood flow to the heart.
Accordingly, there is a need in the art to find methods of making a variety dehydrated sugar compounds and derivatives thereof that is cost effective and efficient.